Gasification of combustible materials



July 28, 1953 R. RUMMEL GASIFICATION OF COMBUSTIBLE MATERIALS 2 Sheets-Sheet 1 Filed May 12, 1949 .HH klB ,9 INVEgTOR. I

y 8, 1953 R. RUMMEL 2,647,045

GASIFICATIQN OF CQMBUSTIBLE MATERIALS Filed May 12, 1949 2 Sheets-Sheet 2 AAMMAN AAAAAAA A. O E 29 2 h *U 4 44 43 19 3 Fig.9 Fig.1!)

IN NTOR.

Patented July 28, 1953 GAslFlCATllgN OF COMBUSTIBLE ATERIALS Roman Rummel, Dusseldorf-Benrath, Germany Application May 12, 1949, Serial No. 92,832 In Germany December 6, 1948 11 Claims.

This invention relates to new and useful improvements in the gasification of combustible materials.

The gasification of combustible materials and particularly of coal is conventionally practised for the recovery of industrially valuable combustible gases such as producer gas, Water gas, mixed or Dowson gas, etc. The formation of these gases essentially involves two types ofreaction. The first is substantially endothermic in nature, and the second is substantially exothermic in nature.

In the first type of reaction the combustible material, such as coal, is brought to relatively high temperature and preferably incandescence and is then contacted with an endothermic gasification agent, i. e., an agent capable of oxidizing combustible material, such as coal, with absorption of heat. Such endothermic reactants are, for instance, water and CO2. dothermically split into hydrogen and oxygen, and thus reacts with the combustible material to furnish a mixture of carbon monoxide and hydrogen conventionally termed water gas." CO2 is endothermically decomposed into CO and oxygen, reacting in this manner to furnish 2C0.

In the second type of reaction a combustible material, such as coal, is contacted at relatively high temperature with a suitable exothermic, gasification agent, i. e., an agent capable of oxidizing combustible material, such as coal, with generation of heat. Such exothermic reactants are, for instance, suitable combustion supporting gases such as oxygen, air or oxygen enriched air. Depending upon the amount of combustion supporting gas used, the exothermic oxidation of combustible material, such as coal, may be guided to the formation of CO or CO2 or variable mixtures thereof.

Gasification of combustible materials with an endothermic reactant produces a rich gas, i. e., a gas high in combustible or B. t. u. value. The heat loss, however, which is involved in the endothermic reaction necessitates frequent periodic re-heating of the combustible material to the required reaction temperature. One method of accomplishing this is by alternately subjecting the material to be gasified to an endothermic and exothermic gasification reaction, i. e., contacting the material alternately with an endothermic gasification reactant such as steam or CO2, and the exothermic gasification reactant such as oxygen, air, or oxygen-enriched air. In the exothermic reaction, the temperature is then again sufficiently raised to be available for the Water is en-,

endothermic gasification step. The resultant gases can then be separately recovered. If heat is the primary consideration in the exothermic step, that reaction is usually carried to the substantially complete combustion of the combustible material to CO2. Alternatively, if it is desired to obtain a combustible gas, the reaction is carried only to the partial combustion of the material to CO. Should non-combustible diluents be present in such gas, such as varying proportions of CO2 or of N2 (introduced it air was used), a so-called lean gas results. When continuous operations are desired, it is conventional practice to simultaneously contact the material to be gasified with the endothermic and exothermic gasification reactants. Thus, for instance, steam or carbon dioxide together with oxygen, air, or oxygen-enriched air, are passed into contact with the heated coal. From this is then recovered a so-called mixed gas which is higher in combustible and B. t. u. value than lean gas but lower in combustible and B. t. u. value than rich gas.

All of the hitherto methods and devices to carry the same into effect have in common the disadvantage that they require a combustible material, such as coal, which is relatively compact, which will not tend to lose that compactness when subjected to relatively high temperatures, which should be substantially free from small particles and fines, and which should not tend to bake together at the temperature of reaction.

Furthermore, the hitherto known procedures and devices do not lend themselves readily to the gasification of combustible materials of a bituminous nature, as, for instance, bituminous coal or brown coal, peats, bituminous shales, etc. When subjecting these bituminous substances to gasification, some of the bituminous constituents, either as such or in the form of partial decomposition products, pass into the gas to be recovered, thereby either impairing the value of such gas for many purposes or necessitating special, and at times, costly purification.

Another drawback to which most of the hitherto known gasification procedures and devices for the recovery of combustible gases are subject, is the accumulation of ashes or clinkers which necessitate discontinuance of operations for their periodic removal. This latter disadvantage, however, is avoided in a procedure which has found industrial application and in which a combustible material, such as coal, is treated with soda ash,

' usually with the further addition of lime to thereby convert the relatively high melting residual silica and alumina compounds into lower melting products. The latter then form a slag which is molten at the relatively high temperature of gasification, thus permitting the residues to be continuously removed from the reaction zone. Also this procedure, however, is still subject to the other disadvantages and drawbacks above mentioned, requiring relatively high grade coal compactness of the individual pieces, absence of The foregoing and still further objects of the "invention "may be "seen train the following description read in conjunction with the drawings in "which:

Fig. 1*is a' diagrammaticside view representation illustrating -one embodiment of the device in-accordance With the invention;

Figs. 2,4 and 6 representrespectively diagrammatic side view representations of alternative embodime'ntsof the device in accordance with the "invention;

Fig.3 shows a diagrammatic cross-section throughthe'construction of Fig. 2 on the plane 'AB thereof;

Fig. 5 illustratesa'diagrammatic cross-section- ;al View through the construction shown in Fig. 4 on the-plane C'-D thereof;

Fig. '7 illustrates a diagrammatic side view representation of a 'preferred embodiment of the device in accordancewith the invention, and showing various ancillary structural arrangements; "and Figs. 8, 9 and 10 respectively show diagrammatic cross-sectional representations or parts thereofillustrating alternative means for the inheater-inn of reactants into the device in accordance -with the intention.

Referring to Fig. 1, a conventional tower i is 'pr'ovided'at'the'bottom thereof With the molten "slagreservoiror' tub 2. Gas nozzles 4 are pro- 'videdin eccentric position at thebotto'm oi tub "2 and 'a'ieSu'pplied by'a suitable exothermic re- 'actant su'ch as' 'oxygen, air, or oxygen-enriched air from a source 8 through duct '5 and manifold *9. A'suitablydriven feeder for combustible material, such as the worm'feeder 3, is provided, with its feed end *Ea passing into tub 2 on one side -thereofand preferaltlly near the bottom. Feeder "3 is providedatone end with hopper opening 5 for feeding particl'ed coal material as, for in- 'st'an'ce,brown'c'oal, and'preferably more or less granular coal, intot'he feeder 3. A duct ii'entering the feedert at the feed end of the Worm is provided for theadmission of an endothermically reactinggasirymg agent su ch as steam, CO2, or

the like.

In the practical operation of the method in accordance with the invention utilizing the arrangement shown in Fig. 1, tub 2 is filled with molten slag. A useful slag may be any slag compri'singmixtures or reaction products of different oxides, the most common and important of which are silicaQl'ir'ne and alumina. Oxide mixtures in the slag may be present as binary or as ternary systems, aswell as in the form of various eutectics-between different oxides, as is-well unto more or less-granular for coal products.

necessar slag may be individually prepared by charging I the -w'ater dontenttn'e'ieor is earned, thus Tu steam for-participation inthe endothei'mi'c asification reaction. At th'e same tiine, -the e'x'bloderstood in the art. Slags useful in accordance with the invention may b individually produced, if desired, in accordance with practices conventional in, for instance, metallurgical processes, or, they may be conveniently obtained by way of the slags used in such processes as, for instance, in the reduction to metal of, for example, iron ore. Alternatively, the-slag may be obtained, in accordance with my preferredpractice, by Way of the substantially non-combustible residues of In that case the slag may be obtained for instance from a coal gasification procedure conducted under conditions of slag formation with the addition of soda ash and lime (if Most conveniently, however, such the slag reservoir or tub 2 with coal, soda ash and lime in appropriate proportions, as are well understood in the art, and then subjecting the charge to gasification or combustion at high temperatures in the hitherto knowngm'anner, to

forma'molt'ensl'ag. If the particular typebr coal used already carries sufficient Ca containing constituents as, ior instance, aliiney shale, the addition of lime'may be-omitted.

Granular coal, such as bituni'inous'coaL is fed into the hopper op'ening' fi, being thence traitsporte'd'by reed worm -3 into the molten si'a'gdn tub 2. A combustion supporting "gas such as oxygen, air, or oxygen-enriched 'a'ir, is injected with relatively high Vei'oc'ityth'roiigh nozzles 2 into the molten slag within tub '2. The introductionof high velocity combustion supporting gas imparts a certain turbulence to the inolt'en slag, and the eccentric position' of the 1ioz'zl'e 'witli respect tothe'bottomof the slag'tub 'z imparts at the same time to the'slag' a circulatory-motion as, for instance, indicated b'y tlieari'ows ii). *An endothermic gasification reactant gas such as steam, CO2, or'the -ik'e, is introduced into the molten slag tubi and prete'i'ablyin-a'manner serving simultaneously to aid the feeding of a combustible 'inaterial such as coal into the inolten slag. Thus, as illustrated in F-ig. lgan endothermic gasification rcaetant, such as' steam or"-G-Oz, is passed through ductfi andpreferably under pressure .to an through duct thence issuinto the molt this 1 'endotl'ierm a 1 slag in tub *2. AS illustrated, reacting gas'ent'ers at -the feed e'nd or wo'lln feed 3 and aids in thefurther transport of the combustible material; passing the sa rneavith a certain-velocity 'into the inoltn slag bath and thus also aiding the di'stributionwf the combustible material therein. This distribution is further supported by' the turbulent inotion imparted to the 'r'nolten slagby the injection effect of the combustion supporting gas issuing from nozzles *4.

Within the preferred procedure-the combustible material asfior instan'cc,'co'al, is converted Why the use ofyfor instance, suitable spii'icd roliers (notshown) ,and may be-intro'ducedt ugh'fthe'hopperopening 5 without preliminar dr yizig; i. with'a 1 moisture content as it 'isobtained from the 'mines. The

moisture contentof "the coal thus {introduces in actants. The coal 1 may be subjected, if desired, to apreliniinary drying operation.

As the-moist coal "enters th'efl'molten slag' b'a th, 'lmost explosively is'hin'g and finely distributing .5 into the molten slag further aids the distribution of the particles of combustible material, such as coal, in the molten slag. If desired, it is possible to use the moisture content of the coal as the sole source for the endothermic gasification reactant, in which case additional endothermic reactant gas need not be introduced through duct 6.

However, it is preferred to introduce some aseous agent through duct to aid the feeding of the combustible material into the slag bath and when it is desired to solely rely upon the moisture content of the combustible material as the source for the endothermic gasification reaction, the gas supplied through duct 6 may then be any other suitable gas, including, if desired, a combustion supporting gas or an inert gas. It is, of course, understood to avoid in such case any gas that might interfere with the desired gasification of the combustible material or may cause the presence of undesirable constituents in the gas mixture passing off through duct ll.

As the molten slag circulates by the impelling force of the high velocity combustion supporting gas issuing through nozzles i and as schematically indicated by arrows iii, the finely distributed carbon particles are thus brought into constant recurrent intimate contact with both the endothermic and the exothermic reactants. The exothermic reactant introduced through nozzles l, such as oxygen, air, or oxygen-enriched air, causes a combustion with the liberation of heat. The endothermic reactant as, for instance, water vapor, introduced for example by way of the moisture content of the combustible material, reacts to form with the combustible material 00 and H2, consuming heat in the reaction. If CO2 were to be introduced as endothermic gasification reactant, further amounts of CO would be produced. It is possible to so adjust the amount of combustion supporting gas through nozzles 13 that the heat liberated in the exothermic reaction will substantially balance the heat consumed in the endothermic reaction, so that the bath of molten slag within tub 2 remains at a substantially uniformly constant temperature.

Thus, within the broad concept of the invention, gasification of combustible materials, such as coal, is obtained by substantially continuously distributing a normally solid combustible material such -as coal in substantially particled and preferably granular form in a molten slag, and substantially continuously intimately contacting said combustible material while so distributed with a combustion supporting gas and with an endothermic gasification reactant, and recovering a combustible gas mixture therefrom.

Among the advantages enjoyed by the procedure in accordance with the invention are the fact that the same lends itself satisfactorily to the use of bituminous materials. The combustible material such as coal, whether bituminous or any other type, does not require any particular degree of firmness or compactness, need not be free from fines, and need not possess non-sintering or non-baking characteristics. If a bituminous material, such as soft or brown coal, peat, shale, or the like, is used, the procedure in accordance with the invention permits the gasification reaction to proceed in such manner that a minimum of distillation products, traceable to the bituminous constituents of the material, is found in the recovered combustible gas. Thus, the gasification of bituminous materials can proceed to the recovery of a combustible gas directly'usable fed by duct l.

for most industrial purposes without the necessity of special scrubbing or purifying treatments.

The preferred embodiment of the invention, as exemplified by a number of variations, is shown in Figs. 2 et seq. It is essentially concerned, in the application of the broad principle of the invention, with the separation of the gases resulting respectively from the endothermic and exothermic reaction phases.

As for instance illustrated in Fig. 2, there are provided two separate towers la and lb having the gas lead-offs i la and l lb respectively. A slag reservoir or tub is provided having the sub-portions 2a and 22) respectively. Ducts l2 and I3 interconnect sub-portions 2a and 2b and are preferably so arranged that duct l2 leads from a point just below the surface of the molten slag in the tub at 2a to a point adjacent the bottom of the tub at 2b, and duct 13 leads from a point just below the surface of the molten slag in tub at 2b to a point adjacent the bottom of the tub at 2a. The bottom of the slag tub portion 2a carries nozzles t (see Fig. 3) issuing from manifold 9, A multiple number of inlets for the combustible material such a coal, and for the gaseous endothermic reactant of the type and arrangement shown and described in connection with Fig. 1 are provided, passing these materials through the ducts 6a into the molten slag within the tub portion 21) and preferably at a point adjacent the bottom thereof.

The introduction of materials into the structure illustrated in Fig. 2 proceeds essentially in the same manner as above illustrated in connection with the device exemplified by Fig. 1. In this case, however, the combustion supporting gas issuing with a relatively high velocity from nozzles i into the molten slag in tub portion 2a imparts turbulent agitation to the bath and at the same time a motion in the direction of the arrow, thereby forcing a molten slag current flow into and through duct l2, thence as indicated by the arrows into and through slag tub portion 21), and thence into and through duct l3 back into slag tub portion 2a. As combustible material such as coal enters through ducts 6a into the slag in tub portion 2b, it is distributed therein and picked up by the circulating slag and thusly carried through duct is into the molten slag within tub portion 2a. The gaseous endothermic reactant, such as water, introduced for instance by way of the moisture content of the combustible material or separately introduced in the form of steam, passes through the slag, being intimately contacted therein in tub portion 2b with the well distributed combustible material as it is circulated and agitated by the slag current which is set up by the impeller effect of the high velocity combustion supporting gas issuing through the nozzles 4 into tub portion 2a. The gaseous endothermic material reacts endothermically with the combustible material in the tub portion 2b and the gases resulting from that reaction as, for instance, a high grade water gas, are recovered in the tower lb by way of the lead-off llb. The non-gasified portion of the combustible material, such as coal, is carried by the slag current into the tub portion 2a and is there exothermically reacted with the combustion supporting gas such as oxygen, air or oxygen-enriched air issuing through nozzles c, thereby replenishing the heat loss incurred by the endothermic reaction within tub portion 21). The thusly reheated slag (and the balance, if any, of non-gasified combustible material) is recycled through duct l 2 back into .ofits heat. 'It'. is however possible-to so adjust the. reaction conditions; including the volume ,of combustion supportingigas, that/a relatively large component ofCO'is obtained in the gasmix passing from tower a,'so that agasof sufficient combustion value isobtained to makerits recovery .practical for certain limited purposes.

There is thus broadly defined within the preferred embodiment'of the invention theisubstantially continuous circulation of molten -=slag through a'first and secondreaction zone, substantially continuously introducing particledcombustible material of the coal type in saidslagrin said first reaction zone, substantially continuously introducing :an: endothermic gasification reactant for said material into said-slag in said firstzone, substantially continuously introducing a combustion supporting gas intosaid slag in said. second zone, and substantially continuously sepa- "rately recovering the gaseous'products of reaction from at least' said first zone.

l' Figs. 4.:and adiagrammatically illustrate a variationof;the deviceshown in Figs. 2 and -3. there exemplified, theislag tub comprises-the lower .portion of a tower carrying the partition sitsextendingtozjust below the liquid level for :the molten slag.: ini the slag-tub, and, separating \the' towenuinto the educt portion lc above reac- .tion 20119520 and the educt portion id above the :reactiomaone 2d. -A multiple number of "cornvbustible .materialian'd endothermic reactant yfeed .units3 am providedthe ducts Ga ofwhich enter the .bottom .of the reaction zone 2d at :one side thereof. The :nozzles '4 for the combustible gas supplied byi-way-wof-duct I and maniioldeare warrangedl-a't%the bottomof the reaction zone'2c at one 'side thereoi and in .a .position generally a'bout diagonal withzrespect tothe positionofi the entrance-openings of .the. ducts- 6a. The impelling action :of the: high "velocity combustion 'supporting gas :issuing :from nozzlcsfl will causemolten slag to flow. upwards in zone 2coverito'andidcwnwards inc-zone. 2d. The introduction of gaseous endothermicreactant, and particularly: whena'ccentuated' by the introduction under pressure-of a gaseous agent byway of duct' 6, will cause an upward current of slag in zone 2d'over to-and downwardin zone 2c. In view ofthafact'l'that the direction of the; current essentially controlled by nozzles: 4%and:that of the current-essentially controlled bytheend openings of ducts-5a arenot in directzjuxtap'osition, the injection openings of nozzles 4 andt'ofxducts'fia' operate in-a'manner to form'a substantially recycling current, substantially as illustrated by the arrows within'the: slag tub-andsh'own iirliigs. 4 and- 5.

a l 1 still 2 further variant in accordance with the rpreferred. embodiment of the invention is for 1instanceiiilustratedxirrFig. 6. -As there-shown, a *more or less' ushaped tower is used,'havingiegs le a d '1 f and.=. gaslead-"ofis-i l e and l lfirespec- .=.tive1y, .Aj artition i zprovidedrin the lowenpor- :75

tion of the 'U, separating the same into the reaction zones 2e-and -2f, and defining .the ducts I1 and 18 respectively between these two zones. The liquid level for the molten slag is provided -So as to extend into the respective .portions la and if. The duct 2'', manifold 9, and nozzle arrangement i (for the combustible gas) are mounted below the reaction zone-2e in a position somewhat higher than the bottom of the U,.to provide for a nozzle discharge level above the horizontal portion of the duct [8. Feeding duct 6a (forcombustible material and gaseous endothermic reactantyis arranged to pass into the reaction zone 21 at a point below the surface .of the molten slag, at which point it will be seized and carried away by the downwardly directed current. The impelling force .of the high velocity combustion supporting gas issuing from nozzles 4 causes the slag to circulate in the direction of the arrows from zone 2e to and throughduct l1, thence to and through zone 2;, thence to and through duct l8 and back into zoneZe. Whereas thus in the previously described embodiments exemplifying devices in accordance with the invention, the endothermic reaction is carried-out in an upwardly directed stream, Fig. fi-illustrates an embodiment where such reaction is accomplished while the combustible material is passed through the endothermic reaction zone in a downwardly directed stream.

The device shown in Figs. -7 and 8-exemplifies a further preferred practice and structure in accordance with the invention effectively utilizing the heat of the produced gases for the pre-heating of the gasiiying agents, generation of steam, and pro-drying of combustible material. There is also illustrated in Fig. '7 astill further variant with respect .to the circulation varrangementior the moltenslag bath in that, in this case, the combustion supporting gas nozzles and entry ducts for the combustible material and endothermic reactant are so. arranged that a substantially horizontalcirculatory motionof the molten slag is obtained.

A tower is separated by the partition .I'Ga into the portions lgand !h. A slag tub'is arranged at the bottom of the tower, and the partition lea extending to below the level of the molten slag within the tub, defines the reaction zones Er and 2h. Combustible material such as coal is fed into reaction zone 2h by way of the worm feed 3. Combustion supporting gas is 'blown into the molten slag in zone 2g by way of the nozzles l9 connected to manifold fiilsupplied by 'cluct d2.

Nozzles it and the feed'ducts to of worm feeds 3 enter their respective reaction zones in a downwardly inclined position, beingat the Tower Ih carries within the walls thereof suitbiecooling means such as water pipes (not shown), which end in water drum-tanks wand 2!.

Cooling, racks having water cooling pipes are diagonally, secured in the .upper tower portions. These are, for instance, diagrammatically indicated by the racks 22 and 23'in'the tower :portion lg, and theracks 24 and 25 in the tower lportion'ih. These cooling racks serve the purpose of liquefying or solidifying portionsof slag thatmay be propelled'upwardly along with the reaction eases.

:Oneendof thecoolingpipes for each pair of racks 22-43 and 24-25 is attached to a source of water supply and preferably to the water tank drums 20 and 2i comprising pro-heated water resulting from the cooling pipe system built into the walls of the tower portions lg and I h. The other end of the cooling pipes of the set 2425 feeds into the super-heater 26. The effect of the hot gases passing the cooling racks is to convert the water therein into steam, which passes into the super-heater 26, in which it is super-heated by the passage of the hot reaction gases in tower portion Ih. Super-heater 26 is connected with the steam reservoir 21 and has the steam drawoff duct 28, whence super-heated steam may be passed off to any industrial usage.

Suitably broken coal, such as brown coal, as for instance by the use of a conventional spiked roller arrangement (not shown), is continuously carried by the endless band 29 into silo 30 whence it passes into the drying duct 3 I The pro-cooled but still hot reaction gases, drawn off the top of tower portion Ih by way of duct He, pass into the bottom of the drying column 3! in which they carry the particled coal upwardly in a stream or current of gas, at the same time drying the same to a predetermined moisture content. The gas and particled coal pass into the duct separator 32 in which the gas is freed of coal dust, being thereafter passed through duct 34 into and through washer 35 and thence out through duct 36, being now ready for industrial use. Blower 31 is provided to draw any portion of the cooled gas passing through duct 34 into the hot gas passing through duct lie to the bottom of drying column 3|. In this manner, the temperature of the gas for drying and transporting the particled coal upwardly in drying column 3i can be adjusted to obtain for the coal the desired predetermined moisture content. The coal is then passed from separator 32 into the hopper 33 whence it is fed by way of the worm feeds 3 into the reaction zone 2h.

The reaction gases, cooled by the cooling racks 22, 23, are passed from tower lg by way of duct I I into a suitable heat exchanger 38. Such heat exchanger may be conventionally provided, for instance, with a multiple series of cooling racks and are usually arranged in pairs so that one of the heat exchangers can receive the hot gas to be cooled (hot blowing), while the other, having I previously received such hot gas, now receives a cooled gas (cold blowing) to impart thereto, by heat exchange, the temperature of the racks. In the illustration of Fig. 7 only one of such pair of heat exchangers is illustrated. Assuming that the racks of heat exchanger 38 have been hot blown and the reaction gases passing out through duct Hf are now being cooled in heat exchange relation in a second re-generator (not shown), the air pump 4!! blows air through duct 4! into the heat exchanger 38, thereby preheating the same in heat exchange relation with the previously hot blown (from the reaction gases of tower portion lg) racks of the exchanger. This preheated air is then passed through duct 42 into manifold 43 and by way of the nozzles i9 into the reaction zone 29!.

The gas issuing from duct 36 is substantially free from undesirable impurities, it is free of steam and coal dust, and can be passed off directly to the intended industrial use. In the particular embodiment shown in Fig. '7, the amount of air introduced by way of nozzles i9 is preferably such that the combustible material circulated with n 1 1 .6 m l en S g 1. reaction zone 10 2g is substantially completely combusted, and the gas passed off through heat exchanger is passed out of the exchanger by way of duct 39 leading to chimney elimination.

As will be apparent from the foregoing, the novel device in accordance with the invention for the improved gasification of combustible materials with gaseous endothermic and exothermic reactants to recover thereby industrially valuable combustible gases within the broad concept thereof, essentially comprises means defining a molten slag reservoir, nozzle means for introducing high velocity combustion supporting gas into said reservoir, said nozzle means being positioned and arranged to impart to molten slag in said reservoir a cycling motion, means for introducing substantially solid gasifiable combustible material such as coal into said reservoir, means for introducing into said reservoir simultaneously with said combustible material a gaseous endothermic gasification reactant therefor, and means for recovering gaseous reaction products from said reservoir.

A preferred device in accordance with the invention essentially comprises means defining a first slag reservoir reaction zone and a second slag reservoir reaction zone, nozzle means for introducing high velocity combustion supporting gas into one of said reaction zones, said nozzle means being positioned and arranged to impart to molten slag in said first reaction zone a circulating motion over to, through, and back from the other reaction zone, means for introducing combustible material into said other reaction zone, means for introducing simultaneously with said combustible material a gaseous gasification reactant therefor into said other reaction zone, and means for separately recovering the reaction gases produced in each of said zones.

It will be generally understood that it is desirable that the path of travel for the gasification reactants through the molten slag, whether in the endothermic or exothermic phase, is preferably so dimensioned and the introduction of combustible material so related thereto, that the gasification reactions between the combustible material and the gasification agents are essentially completed at the end of about one cycle along the path of travel of the combustible agent. It is however well within the skill of any competent engineer to appropriately correlate to this end the velocity of the gasification agents entering the molten slag bath, the height and/or volume of the slag bath, as well as its horizontal dimensions.

Further variations in combustion supporting gas nozzle arrangements are, for instance, illustrated in Figs. 9 and 10. As shown for example in Fig. 9, the nozzles 44 supplied by the manifold 43 are substantially horizontally disposed to propel high velocity combustion supporting gas in a substantially horizontal direction into the slag reservoir or tub 22'. The horizontal angular disposition of these nozzles 44, however, is substantially similar to that of the nozzles 19 illustrated in Fig. 8 to thereby set up a substantially horizontal circulatory movement of the slag within the reservoir 22', and continue the impelling of the circulatory slag current thereby created. The nozzles 45 of Fig. 10 supplied by manifold 43 are arranged at the bottom of the molten slag tub 27' and are mounted to issue the high velocity combustion supporting gas at an angle to the vertical, to thereby impart current movement to 11 the slag bath substantially in the direction of the arrow.

It is understood that when proceeding in accordance with the invention, additional molten slag is continuously formed as part of the gasification reaction of the introduced combustible material. There should, therefore, be preferably provided either conventional overflow arrangements for the purpose of continuously withdrawing excess molten slag, or, alternatively, con ventional means should be provided for a periodic withdrawal of such excess slag. The excess sla itself, with or without additives, may be used for the information, such as by casting or molding, of building blocks or similar materials. It mayalso be desirable from time to time, or, continuously (as conditions may require) to add suitable slagging additives for appropriate slag conversion of the alumina and silica constituents continuously introduced by the combustible material.

I claim:

1. In the gasification of combustible material of the coal type, the improvement comprising substantially continuously introducing such a material in substantially particled form into a molten slag below the surface thereof, substantially continuously contacting said material in said slag with a combustion supporting gas and with an endothermic gasification reactant for said material, and recovering a combustible gas mixture therefrom.

2. Improvement according to claim 1 in which said slag is substantially continuously moved in a substantially cyclic current.

3. Improvement according to claim 1 in which said combustion supporting gas is substantially continuously introduced into said slag in a direction and with a velocity sufficient to thereby cause said slag to move in a substantially cyclic current.

4. Improvement according to claim 3 in which at least a portion of said endothermic reactant is H2O introduced by way of moisture content of said combustible material.

5. Improvement according to claim 1 in which said slag is substantially continuously moved in a substantially cyclic current, in which said combustible material and said endothermic reactant are substantially continuously endothermically reacted in a first portion of said slag current defining a first reaction zone, in which said combustion supporting gas is substantially continuously exothermically reacted with remaining combustible material in a subsequent portion of 12 said slag current defining a second reaction zone, and in which there is separately recovered a combustible gas mix from said first zone.

6. Improvement according to claim 5 in which said combustion supporting gas is substantially continuously introduced into said slag in a direction and with a velocity suificient to thereby cause said slag to move in a substantially cyclic current.

7. Improvement according to claim 6 in which at least a portion of said endothermic reactant is H2O introduced by way of moisture content of said combustible material.

8. Improvement according to claim 6 in which at least a portion of said endothermic reactant is substantially continuously introduced as a gas into said slag in a direction and with a velocity sufficient-to co-act with said combustion supporting gas in substantially maintaining such cyclic current.

9. Improvement according to claim 8 in which said combustible material is introduced substantially 'in' and with said endothermic reactant gas.

10. Improvement according to claim 8 in which a portion of said endothermic reactant is introduced as a gas into said slag in said direction and with said velocity, and in which the remainder of said endothermic reactant is H2O in troduced by way of moisture content of said combustible material.

11. Improvement according to claim 10 in which said combustible material is introduced substantially in and with said endothermic reactant gas.

ROMAN RUMMEL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 529,453 Lorois Nov. 20, 1894 1,559,622 Klotzer Nov. 3, 1925 1,592,861 Leonarz July 20, 1926 1,799,885 Chavanne Apr. 7, 1931 1,803,221 Tyrer Apr. 28, 1931 1,904,908 Voorhees Apr. 18, 1933 2,111,579 Winkler et al. Mai. 22, 1938 2,521,195 Wheeler Sept. 5, 1950 FOREIGN PATENTS Number Country Date 606,765 Great Britain Aug. 19, 1948 

1. IN THE GASIFICATION OF COMBUSTIBLE MATERIAL OF THE COAL TYPE, THE IMPROVEMENT COMPRISING SUBSTANTIALLY CONTINUOUSLY INTRODUCING SUCH A MATERIAL IN SUBSTANTIALLY PARTICLED FORM INTO A MOLTEN SLAG BELOW THE SURFACE THEREOF, SUBSTANTIALLY CONTINUOUSLY CONTACTING SAID MATERIAL IN SAID SLAG WITH A COMBUSTION SUPPORTING GAS AND WITH AN ENDOTHERMIC GASIFICATION REACTANT FOR SAID MATERIAL, AND RECOVERING A COMBUSTIBLE GASMIXTURE THEREFROM. 